U of T graduate students Erica Tennenhouse, right, and Amber
Walker-Bolton were among a group who complained about the euthanizing of
primates like the crab-eating macaque shown on their computer screen. The
School of Dentistry had been using them in research.

RICK EGLINTON/TORONTO STAR

Louise Brown - Education Reporter

For seven years, scientists studied their brains in a research project
deemed so valuable it won a national award.

In their off-hours, the two young females played with toys, watched TV,
ate fruit and hung out together in their home on the University of Toronto
campus.

That home was a cage for the two monkeys, "cynomolgus macaques" bred in
Texas for research.

And when they were put to death earlier this month so scientists could
analyze their brains, it marked the end of primate research at Canada's
largest university.

"They were our very last �non-human' primates and we have no intention of
using any more. Technology now lets us get the same information from smaller
animals," said Peter Lewis, the U of T's associate vice-president of
research.

Moreover, the university has been using fewer primates "because of the
cost, the availability and the ethics," said university veterinarian Dr.
George Harapa.

It was ethical concern that prompted five U of T graduate students in
primatology to try to spare these monkeys from death last week and have them
sent to a primate sanctuary such as Story Book Farm, near Sunderland
northeast of Toronto, a sort of retirement home for monkeys.

"I was surprised by the nature of the experiment � it sounded like a
horror movie; stimulating parts of the brain to see how the monkeys react,"
said PhD student Erica Tennenhouse, who co-wrote a passionate letter to
university officials last week asking that the two animals be spared and no
further primates be used for research.

They learned the animals were already dead, euthanized by lethal overdose
of anesthetic for the final stage of the study.

"I was disappointed. These are creatures capable of enjoying a
compassionate retired life even after years of trauma," said graduate
student Amber Walker-Bolton, who learned about the experiment at a training
course she attended before going to Madagascar to study ring-tailed lemurs.

Yet neuroscientist and dentist Dr. Barry Sessle, who led the study,
insisted the primates were not subjected to pain, nor restrained for up to
12 hours at a time, as students had charged.

"It wasn't pain research and the animal doesn't feel the electric
stimulation from the electrodes because brains aren't sensitive," said
Sessle.

"Most of the pain research I do is on sub-primates (rodents) and they're
anesthetized."

He will continue to do monkey studies in partnership with a lab in
Chicago.

The monkey study inserted electrodes into the cerebral cortex to unveil a
treasure trove of cellular secrets about how the mind adapts when the face
is changed due to injury, stroke or even the loss of teeth.

"One of the advantages of using monkeys is that they are intelligent so
we can train them to do something and then study how they learn how to do it
� we had them learn to protrude their tongue, for example, in a particular
position � which gives us knowledge we can use to help improve therapeutic
approaches," said Sessle.

Post-mortem analysis is a crucial piece of the puzzle, he added.

Of some 50,000 vertebrates used each year for scientific research at the
U of T, about 85 per cent are mice and rats, thanks to new imaging
technology and miniaturization, said Harapa. The rest are mostly fish, plus
a few rabbits.

"We stopped using dogs and cats a few years ago too. We can do so much
research now by genetically modifying a mouse," said Harapa.

"Under a sector microscope you would hardly know the difference between a
human heart and that of a mouse."

The university uses half as many animals in research as it did in the
1980s, Harapa said.

That's good news for Tennenhouse. "I'm thrilled to hear there will be no
more primate research and I hope other universities follow our lead."